It may be generally useful to provide a system and method that generates periodic movement of a mechanical device. Examples include pendulums, tuning forks, quartz crystal resonators and the like. The oscillating structures can be used as frequency determining devices in electronic circuits. A quartz crystal may be fitted with electrodes so that mechanical vibrations in the crystal may be amplified by an electronic feedback amplifier to produce sustained oscillations at a frequency set by the geometry of the crystal. MEMS systems have been used to provide micrometer-scale mechanical resonators for the same purpose. Cantilevers and drumheads can be manufactured and coupled to electronic feedback amplifiers so that the characteristic mechanical resonant frequency of the MEMS structure determines the oscillation frequency of the electronic circuit.
These techniques for providing a fixed frequency oscillator are well known and often applied to today's communications and timekeeping equipment. However, these circuits must be provided with electrical power to overcome the energy lost in the circuit due to the unavoidable losses inherent in electronic oscillator circuits. This need to electrically power these circuits is a disadvantage in applications where the available electrical power is small or non-existent. It would be advantageous to provide oscillators which operate without the need for external electrical power or other circuitry to establish and maintain oscillation at a characteristic frequency.